Analog Simulation of a Hybrid Gasoline-Electric Vehicle

Abstract

Hybrid vehicles using both internal combustion en gines and electric motors represent one way to reduce fuel consumption. Our demonstration project envi sioned more than halving the fuel consumption of a passenger vehicle by reducing greatly the capacity of its engine and adding regenerative braking and an all-electric range. We also envisaged maintaining the same performance as current passenger vehicles. A 0-6 000 rpm gasoline-driven internal combustion engine, two 0-7800 rpm electric motors, a 0-7800 rpm flywheel, and lead-acid batteries are the major com ponents assembled using a mechanical epicyclic gear box. An EAI 681 analog computer allowed us to examine quickly the effects of engine capacity, fly wheel size, battery voltage, gear ratios, and mode of operation. An external potentiometer control on the computer allowed the operator to drive the vehicle through any acceleration cycle on level ground. We have shown that a 1.3 litre gasoline engine, two 13 kW separately excited direct current electric motors, a 38 kg flywheel, and a 48-volt battery pack will provide the same maximum performance as a conventional 4.1 litre internal combustion engine with automatic transmission at vehicle speeds below 60 km/h, and lower but satisfactory highway performance up to a top speed of 130 km/h. The transmission has under gone laboratory tests; it is to be road-tested in the first half of 1982.